|Hurkman Ii, William|
Submitted to: Federation of European Biochemical Societies Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2003
Publication Date: 7/17/2003
Citation: Wong, J.H., Balmer, Y., Cai, N., Tanaka, C.K., Vensel, W.H., Hurkman, W.J., Buchanan, B.B. 2003. Unraveling thioredoxin-linked metabolic processes of cereal starchy endosperm using proteomics. Federation of European Biochemical Societies Letters.2003. 547: 151-156 Interpretive Summary: Proteins in the endosperm of wheat grain were investigated to gain further insight into the regulatory role of thioredoxin in cereals. Thioredoxin is a protein with a catalytically active disulfide group that regulates a broad spectrum of biochemical processes. A better understanding of the role of thioredoxin in seeds could be achieved if more wore known about the target proteins. Thioredoxin proteins extracted from the endosperm were labeled with a fluorescent probe, separated by two-dimensional gel electrophoresis, and identified by comparison to an extensive protein map of the endosperm developed in recent studies. We identified 23 proteins, 12 not known to be previously to be thioredoxin-linked. In addition to uncovering these previously unrecognized links to thioredoxin, the results provide insight into the biochemical processes of the cereal endosperm.
Technical Abstract: Application of a thiol specific probe, monobromobimane (mBBr) with proteomics and enzyme assays led to the identification of 24 thioredoxin targets in the starchy endosperm of mature wheat seeds (Triticum aestivum cv. Butte), almost all containing at least 2 conserved cysteines. The identified targets, 12 not known to be thioredoxin-linked, function in a spectrum of processes: metabolism (12 targets), protein storage (3), oxidative stress (3), protein degradation (2), protein assembly/folding (1) and unknown reactions (3). In addition to formulating metabolic pathways functional in the endosperm, the results suggest that thioredoxin acts in redox regulation throughout the life cycle of the seed.